Pre-slit injection site and tapered cannula

ABSTRACT

A pre-slit injection site (34) includes a housing (40) with a flow path therethrough. A first end (42) of the housing (40) carries a pre-slit septum (52). One form of a blunt cannula (98), usable with the injection site (34), carries a locking member (100). When the pre-slit injection site (34) slidably receives the blunt cannula (98), the locking member (100) latches to the injection site (34) and creates a mechanically coupled unit. Another form of the cannula (280) includes a tube having a tapered distal end region (298) and having elongate discharge slots (294) for reducing contact surface area and for directing the flow laterally out of the cannula. The cannula may also include a rounded lead post (330), an annular barb (394), and axially oriented grooves (268). A blood sampling system utilizing an in-line pre-slit injetion site (492) and a shielded blunt cannula (512). An adapter for transferring fluids from a syringe with a blunt cannula to an evacuated tube, including a pre-slit injection site (554) and a shroud covered needle (556) with a rubber sleeve.

This is a continuation-in-part of U.S. patent application Ser. No.07/325,617, filed Mar. 17, 1989, entitled Pre-Slit Injection Site andTapered Cannula, which is a continuation-in-part of U.S. patentapplication Ser. No. 217,004, filed Jul. 8, 1988 (now abandoned), whichis a continuation-in-part of U.S. patent application Ser. No. 147,414,filed Jan. 25, 1988 (now abandoned).

FIELD OF THE INVENTION

The invention pertains to coupling systems usable to transfer materialsfrom one flow conduit to another. More particularly, the inventionpertains to two-part coupling members with a first part including apre-slit septum and second part including a blunt cannula. The pre-slitseptum slidably receives the blunt cannula to effect the coupling.

BACKGROUND OF THE INVENTION

Injection sites usable with pointed cannulae have long been known. Forexample, such sites can be formed with a housing having a fluid flowpath therein. A septum is positioned in the housing closing the fluidflow path.

One injection site usable with a piercing cannula is disclosed in U.S.Pat. No. 4,412,573 to Zbed entitled "Injection Site." The Zbed patent isassigned to the assignee of the present invention.

The pointed cannula can be forced through the septum into fluid flowcommunication with the flow path in the housing. Known injection sitesusable with a piercing cannula can be physically damaged by repetitivepiercing caused by the sharp cannula. This damage, known as coring orlaceration, can result in subsequent leakage.

Due to problems associated with infectious agents, personnel using suchpointed cannulae do so with great care. Notwithstanding careful andprudent practice, from time to time, accidents do occur and individualsusing such pointed cannulae jab themselves.

Injection sites usable with a blunt cannula are also known. For example,U.S. Pat. No. 4,197,848 issued to Garrett, et al., entitled "ClosedUrinary Irrigation Site" and assigned to the assignee of the presentinvention discloses one such injection site. That injection site is arelatively low pressure device having a relatively thin, molded, sealingmember. The sealing member has an opening therethrough.

A blunt cannulae can be forced through the sealing member placing thecannulae into fluid flow communication with a fluid flow pathway in theinjection site.

Injection sites of the type noted above usable with a blunt cannula havethe advantage that the blunt cannula will not pierce the skin of a user.On the other hand, it is important that the pre-slit injection sitereseal with enough force that fluids do not ooze therefrom and thatairborne particulate matter, bacterial or viral matter do not entertherethrough.

Hence, there continues to be a need for a pre-slit injection site whichcan be used with a variety of solutions and over a range of fluidpressures. Further, there continues to be a need for such a pre-slitinjection site which will reliably reseal even after many insertions ofthe blunt cannula.

Such an injection site should be able to receive a large number ofinsertions of the cannula without displaying reseal failure. Such aninjection site should provide for improved alignment of the cannula oninsertion. Improved alignment will result in less chance of damage tothe injection site after repeated insertions of the cannula. Preferably,the injection site would also be usable with a pointed cannula.Preferably, a pre-slit injection site usable with a blunt cannula willprovide a reasonable level of insertion force such that health carepersonnel will readily be able to insert the blunt cannula, yet thecannula will not easily fall from or drop out of contact with theseptum.

SUMMARY OF THE INVENTION

In accordance with the invention, an easily wipeable injection siteusable with a blunt cannula is provided. The injection site includes ahousing which defines a fluid flow channel therethrough. The housing hasa first and a second end.

A flexible sealing member is carried by the housing for sealing thefirst end. The sealing member has a resealable opening therein. Thesealing member also is formed with a curved exterior peripheral surfacesuch that the blunt cannula can be sealingly inserted through theopening and placed in fluid flow communication with the flow path.Further, the blunt cannula can be removed from the opening with asealing member then interacting with the housing so as to reseal theopening.

The housing can also be formed with the first end including an annularchannel underlying the sealing member. The sealing member is subjectedto radially directed forces by a tapered surface of the first end of thehousing. These forces tend to reseal the opening in the sealing member.

The sealing member can be a cylindrically shaped rubber member. Thefirst end of the housing can include an interior tapered surface forreceiving the sealing member and for applying the radially directedforces to the sealing member.

A retaining member carried by the first end of the housing can be usedto retain the sealing member within the housing. The retaining membercan be generally U-shaped. Alternately, the retaining member can beformed as a coiled spring.

The retaining member applies axially directed forces to the sealingmember. In one embodiment of the invention, the retaining memberdeflects the sealing member and forms a curved exterior peripheralsurface thereon. The curved exterior peripheral surface is an easilywipeable surface.

The retaining member deflects or distorts the upper and lower peripheraledges slightly as a result of applying axial forces thereto. When theblunt cannula is inserted into the slit in the sealing member, anannular interior peripheral region of the sealing member deforms furtherand fills, at least in part, the annular channel.

Deformation of this annular peripheral region results in an insertionforce in a range of 2.0 pounds (0.7564 kilograms) to 5.0 pounds (1.891kilograms). Preferably, the insertion force will have a value of theorder of 2.0 pounds (0.7564 kilograms).

The resealable opening in the sealing member can extend entirely throughthat member. Alternately, the resealable opening can extend only partwaytherethrough. In this embodiment, the end of the blunt cannula will beused to tear through the remainder of the sealing member.

The sealing member can be formed in two parts. An exterior cylindricalportion can be slit completely. An interior cylindrical unslit portioncan be provided to seal the site until the blunt cannula is insertedtherethrough the first time.

The interior surface of the first end can be formed with the taper in arange on the order of 5 degrees to 20 degrees. Preferably, the interiorsurface will have a taper on the order of 12 degrees. This taperedsurface permits the use of a cylindrically shaped sealing member.

To provide for leak-free insertion, the length of the slit in thesealing member must be less than one-half the circumference of thecannula being inserted therethrough. Hence, the slit length may exceedthe diameter of the cannula being inserted. In addition, the slit lengthmust be great enough, given the elastic limit of the sealing member, toprevent tearing during insertion.

Further, in accordance with the invention, a coupling system forcoupling first and second fluid flow members together is provided. Thecoupling system includes an injection site which is affixed to the firstfluid flow member. The injection site includes a housing. The housinghas a fluid flow path therethrough.

A sealing member is carried by the housing. The sealing member has aresealable opening therein.

An annular retaining member is carried by the housing and cooperateswith the housing to retain the sealing member therein. Radially directedforces are applied to the sealing member by the housing, thereby urgingthe opening into a resealed condition.

A blunt cannula, affixed to second fluid flow member, has a fluid flowpath therethrough. The cannula carries a locking member for lockinglyengaging the housing when the cannula extends through the opening of thesealing member. When so positioned, the two fluid flow members ar placedinto fluid flow communication.

The locking member can include a luer-type twist lock fitting.Alternately, the locking member can include slidably engageable memberswhich are responsive to axial movement of the injection site and thecannula toward one another.

In accordance with further aspects of this invention, the blunt cannulamay be provided with features that facilitate insertion into theinjection site, enhance fluid flow or dispersion, increase tugresistance, and reduce kickback.

In particular, one embodiment of the cannula includes a tube with aplurality of elongate discharge slots adjacent the distal end. The fluidchanges direction as it passes laterally through the slots and out ofthe tube. The flow area of the slots exceeds the flow area inside thetube. This slot structure enhances fluid flow and inspersioncharacteristics. In addition, the slots decrease the contact surfacearea on the tube exterior so as to facilitate insertion.

In a further modification, the cannula includes a lead post on the tubedistal end to guide the cannula through the slit in the injection site.

In another cannula embodiment, the tube is generally cylindrical and thefluid discharges directly from an open end of the tube. The exteriorsurface of the tube is provided with grooves to reduce the contactsurface area.

In still another cannula embodiment, the tube has a cylindrical portionand a tapered distal end portion which are each about equal in length.The taper facilitates insertion, and the remaining cylindrical portionreduced kickback.

In yet another embodiment, the cannula includes an annular barb whichfunctions to reduce kickback.

Other advantages of a blunt plastic cannula in accordance with theinvention, relative to conventional steel needles include a higher fluidflow rate capacity and simpler one-piece plastic design.

Numerous other advantages and features of the present invention willbecome readily apparent from the following detailed description of theinvention and the embodiments thereof, from the claims and from theaccompanying drawings in which the details for the invention are fullyand completely disclosed as a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view, partly in section, of a prior artpre-slit injection site and an associated blunt cannula;

FIG. 2A is a view in perspective of a catheter positioned in the hand ofa patient with a pre-slit injection site in accordance with the presentinvention positioned adjacent thereto;

FIG. 2B is a perspective view of the catheter of FIG. 2A with a pre-slitinjection site in accordance with the present invention rotatablyaffixed thereto:

FIG. 3 is an enlarged side elevational view in a section of a pre-slitinjection site in accordance with the present invention formed on a bodyhaving a luer twist-lock type connector for coupling to a catheter;

FIG. 4A is an exploded view of a pre-slit injection site, a shieldedblunt cannula and a syringe prior to being coupled together;

FIG. 4B is an enlarged, side elevational view in section of the pre-slitinjection site, the shielded blunt cannula and the syringe of FIG. 4Acoupled together to form a sealed fluid flow system;

FIG. 5A is a view in perspective of a pre-slit injection site prior toengaging a blunt cannula carrying a locking member;

FIG. 5B is an enlarged side elevational view, partly broken away,illustrating the interrelationship between the pre-slit injection siteand the blunt cannula of FIG. 5A;

FIG. 6 is an overall view of a container, an associated solutionadministration set and a pre-slit injection site in accordance with thepresent invention;

FIG. 7 is an enlarged side elevational view, partly broken awayillustrating the relationship between selected elements of FIG. 6;

FIG. 8 is a side elevational view, partly broken away illustrating analternate shielded cannula in accordance with the present invention;

FIG. 9 is a side elevational view, partly in section, of a pre-slitinjection site mounted on a fragment of a solution container;

FIG. 10 is a side elevational view of a fragment of a solution containercarrying, as a single port, a pre-slit injection site;

FIG. 11 is a side elevational view of the injection site and fragmentarycontainer of FIG. 10 prior to being engaged with a shielded cannulacarried by a syringe;

FIG. 12 is an enlarged side elevational view, partly in section, of acoupling system with a pre-slit injection site partly coupled to a bluntcannula;

FIG. 13 is an enlarged side elevational view, partly in section, of thecoupling system of FIG. 12 subsequent to engagement of the two couplingmembers;

FIG. 14 is a side elevational view, partly broken away, of a spikeconnector carrying a pre-slit injection site in accordance with thepresent invention;

FIG. 15 is an enlarged side elevational view of a Y-connector in sectioncarrying a pre-slit injection site in accordance with the presentinvention;

FIG. 16 is an enlarged fragmentary side elevational view in section of acoupling member carrying a pre-slit injection site where the slitextends only partway through the septum;

FIG. 17 is a perspective view of a burette solution administration setcarrying a pre-slit injection site in accordance with the presentinvention;

FIG. 18 is a view of part of a burette solution administration setcarrying a pre-slit injection site being coupled to a shielded bluntcannula;

FIG. 19 is a step in the method of making a pre-slit injection site inaccordance with the present invention;

FIG. 20 is another step in the method of making a pre-slit injectionsite in accordance with the present invention;

FIG. 21 is an initial phase of a final step in making a pre-slitinjection site in accordance with the present invention;

FIG. 22 is an intermediate phase of the final step in a method of makinga pre-slit injection site in accordance with the present invention;

FIG. 23 is a final phase of the final step in a method of making apre-slit injection site in accordance with the present invention;

FIG. 24 illustrates an initial phase in an alternate step of making apre-slit injection site in accordance with the present invention;

FIG. 25 illustrates a final phase of the alternate step in a method ofmaking an injection site in accordance with the present invention;

FIG. 26 illustrates yet another alternate step in a method of making apre-slit injection site in accordance with the present invention;

FIG. 27 is an enlarged, fragmentary cross-sectional view of anotherembodiment of an injection site in accordance with the presentinvention;

FIG. 28 is a cross-section view taken generally along the plane 28--28in FIG. 27;

FIG. 29 is an end view of another embodiment of the cannula inaccordance with the present invention;

FIG. 30 is a cross-section view taken generally along the plane 30--30in FIG. 29;

FIG. 31 is an end view of another embodiment of the cannula inaccordance with the present invention;

FIG. 32 is a cross-sectional view taken generally along the plane 32--32in FIG. 31;

FIG. 33 is a cross-sectional view taken generally along the plane 33--33in FIG. 32;

FIG. 34 is an end view of another embodiment of the cannula inaccordance with the present invention;

FIG. 35 is a fragmentary, side elevational view of the embodiment of thecannula illustrated in FIG. 34;

FIG. 36 is a cross-sectional view taken generally along the plane 36--36in FIG. 34;

FIG. 37 is a cross-sectional view taken generally along the plane 37--37in FIG. 36;

FIG. 38 is an end view of another embodiment of the cannula according tothe present invention;

FIG. 39 is a cross-sectional view taken generally along the plane 39--39in FIG. 38;

FIG. 40 is a cross-sectional view taken generally along the plane 40--40in FIG. 39;

FIG. 41 is an end view of another embodiment of the cannula according tothe present invention;

FIG. 42 is a cross-sectional view taken generally along the plane 42--42in FIG. 41;

FIG. 43 is an end view of another embodiment of the cannula according tothe present invention;

FIG. 44 is a cross-sectional view taken generally along the plan 44--44in FIG. 43; and

FIG. 45 is a view in section of another insertion member for a bluntcannula.

FIG. 46 is a perspective view of another embodiment of a blunt cannulaembodying the present invention.

FIG. 47 is a perspective view of a blunt cannula shield or tipprotector.

FIG. 48 is a perspective view of a heparin lock embodying the presentinvention.

FIG. 49 is a side elevational view of the heparin lock of FIG. 48 injoined relationship with a blunt cannula device of alternativeconstruction embodying the present invention.

FIG. 50 is a cross-sectional view of the heparin lock of FIG. 48 injoined relationship with a blunt cannula device of further alternativeconstruction embodying the present invention.

FIG. 51 is a cross-sectional view of a pre-slit in-line injection siteembodying the present invention in joined relationship with a bluntcannula shown in side elevational view.

FIG. 52 is a perspective view of the alternative blunt cannula device ofFIG. 49 in joined and locked relationship with the pre-slit in-lineinjection site depicted in FIG. 51.

FIG. 53 is a perspective view, partially broken away, depicting thecombination of a syringe and an alternative blunt cannula device of thepresent invention for injecting or removing liquid through a pre-slitin-line injection site, such as depicted in FIG. 51.

FIG. 54 is a perspective view of a blunt cannula shield or tip protectorfor attachment over the end of the blunt cannula device such as depictedin FIG. 53.

FIG. 55 is a cross-sectional view of an alternative blunt cannula deviceparticularly suited for attachment to a syringe as shown in FIG. 53.

FIG. 56 is a perspective view of the blunt cannula device shown in FIG.53 in joined relationship with the pre-slit injection site shown in FIG.51.

FIG. 57 is a perspective view of the blood sample system of the presentinvention with the pre-slit in-line injection site 492 shown in FIG. 51.

FIG. 58 is a perspective view of a "Z" shaped housing for the pre-slitinjection site.

FIG. 59 is a perspective view of the blunt cannula and syringe with arotating shield.

FIG. 60 is a perspective view of a blood transfer unit with a pre-slitinjection site.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While this invention is susceptible of embodiment in many differentforms, there are shown in the drawing and will be described herein indetail specific embodiments thereof with the understanding that thepresent disclosure is to be considered as an exemplification of theprinciples of the invention and is not intended to limit the inventionto the specific embodiments illustrated.

A prior art pre-slit injection site 10 and associated blunt cannula 12are illustrated in FIG. 1. The prior art injection site 10 has acylindrical housing 14 with a fluid flow path 16 therethrough. A firstend 18 of the housing 14 is closed with a relatively thin disc-shapedresealable member 20. The member 20 has a resealable opening 22 therein.

The member 20 is a molded septum with an integrally formed skirt 20a.The skirt 20a is oriented generally perpendicular to the portion of theseptum with the opening 22.

The cannula 12 includes a body portion 24 which carries at a first end ahollow, cylindrical, blunt piercing member 26. As the cannula 12 ismoved in a direction 28 toward the first end 18 of the injection site10, the member 26 slidably engages the opening 22. The sealing member 20is then-deformed adjacent the opening 22 and the number 26 extends intothe flow path 16. A fluid flow path through the cannula 12 will then bein fluid flow communication with the flow path 16 via the hollowpiercing member 26.

In contradistinction to the prior art pre-slit injection site 10 of FIG.1, FIGS. 2A and 2B illustrate a pre-slit injection site 34 being coupledto a peripheral venous catheter 36. The catheter 36 is shown in fluidflow communication with a vein in a hand H of a patient. The catheter 36carries at a proximal end 38 a luer-type female twist lock connector 41.

The pre-slit injection site 34 is formed with a cylindrical housing 40having a first end 42 and a second end 44.

Carried by the housing 40, adjacent the second end 44 is a hollowcylindrical fluid flow member 46. The member 46 slidably engages areceiving member in the housing 38 of the catheter 36, thereby providinga sterile fluid flow coupling as is well known and conventional.

A plurality of internal male luer-type threads 48 is carried by thehousing 40 adjacent the second end 44. The threads 48 will engage theflange member 41 when the injection site 34 is rotated in a direction50. When so coupled together, the catheter 36 and the injection site 40provide a sealed coupling through which fluids may be injected into thevein of the hand H.

FIG. 3 illustrates, in section, further details of the injection site34. A resealable septum 52 is carried by the first end 42 of the housing40. The septum 52 includes first and second spaced apart surfaces 54 and56 respectively. The surface 54 has been forced into a dome-like shapeby annular, U-shaped, swaged end members 58 carried by the first end 42.The dome-like shape of the surface 54 can extend beyond a surface 42a ofthe first end 42. This facilitates cleaning the surface 54.

The septum 52 has a generally cylindrical shape. The septum 52 can beformed of a latex or synthetic rubber material. Alternately, the septumcan be formed of a thermoplastic elastomer. The material used for theseptum 52 should be non-toxic and sterilizable such as by means ofradiation, steam or Ethylene Oxide.

Because the septum 52 is generally cylindrical in shape, it can bedie-cut from a sheet, cut from an extruded rod or molded. The septum 52can have an exemplary diameter on the order of 0.30 inches (0.762centimeters). The height of the septum 52 can be, for example, on theorder of 0.125 inches (0.3175 centimeters).

The first end 42 is also formed with a tapered interior surface 60 whichterminates in an annular channel 62. The tapered interior surface 60 hasa taper in a range of 5 degrees to 20 degrees. Preferably, the taperwill be on the order of 12 degrees. With the indicated size of the abovenoted exemplary septum 52 and a 12 degree taper, diametric resealingcompression of the septum 52 adjacent the channel 62 is on the order of10%.

The channel 62 is bounded in part by a septum supporting ridge 62a. Thechannel 62 can typically have a depth in a range of 0.050-0.070 inches(0.127-0.1778 centimeters).

A peripheral surface 64 of the septum 52 slidably engages the taperedinterior surface 60 as the septum 52 slides into the first end 42. Theannular channel 62 which underlies the interior peripheral surface 56 ofthe septum 52 is provided to permit the septum 52 to deform when a bluntcannula is inserted through an opening 66 therein.

The housing 40 is also formed with a fluid flow path 68 such that fluidsinjected via a blunt cannula inserted through the resealable opening 66can flow into the catheter 36 for delivery to hand H of the patient.

The swaged end members 58 apply axial forces to the septum 52 therebycreating the domed exterior peripheral surface 54. The axial forcesapplied by the end members 58 slightly deform the regions 52a and 52b.In contradistinction, the tapered internal surface 60 applies radiallydirected forces to the septum 52, thereby forcing the opening 66 into aresealed condition.

In an alternate embodiment, the surface 52 could be formed as a flat, asopposed to a domed, surface.

Once the injection site 34 is lockingly engaged with the catheter 36, asealed system is formed through which fluids can be infused into thecatheter 36. The resealable septum 52 closes the fluid flow path 68.

FIGS. 4A and 4B illustrate in combination the injection site 34, a bluntshielded cannula 80 and a syringe of a conventional type 82. The syringe82, as is well known, can be formed with a cylindrical hollow end 84which-carries a male luer-type twist lock thread 86. A hollow centrallylocated cylindrical fluid flow member 88 is in fluid flow communicationwith an interior region 90 of the syringe 82.

The shielded blunt cannula 80 carries at a first end 92 a female luertwist-lock flange 94. The flange 94 will slidably engage the threads 86of the end 84. Hence, the shielded blunt cannula 80 can be locked to thesyringe 82 forming a closed fluid flow pathway. The shielded cannula 80could alternately be formed fixedly attached to the syringe 82.

The shielded blunt cannula 80 carries a cylindrical hollow protectiveshield 96 which surrounds a centrally located hollow, elongatedcylindrical blunt piercing member 98. The cylindrical blunt piercingmember 98 has a total length on the order of three times the thicknessof the septum 52 in order to ensure complete penetration. Thecylindrical blunt piercing member 98 has a diameter on the order of 1/3the diameter of the septum 52. The shield 96 is desirable and useful formaintaining the piercing member 98 in an aseptic condition by preventingtouch contamination prior to the shielded cannula 80 engaging thepre-slit septum 52. Also, the shield helps to align the piercing memberwith the pre-slit septum.

The cylindrical blunt piercing member 98 can slidably engage thepre-slit septum 52, best illustrated in FIG. 4B, thereby extendingthrough the preformed opening 66 therein. As illustrated in FIG. 4B,when the piercing member 98 slidably engages and pierces the septum 52,the region 52a deforms by expanding into and filling, at least in part,the annular channel 62.

The deformation facilitates insertion of the piercing member 98 throughthe slit 66. Subsequent to the piercing member 98 slidably engaging theinjection site 34, the interior region 90 of the syringe 82 is in fluidflow communication with the flow path 68, of the injection site 34 viaflow paths 88a and 98a respectively of the syringe and the bluntpiercing member 98.

In this engagement condition, the septum 52 seals completely around thepiercing member 98. Hence, exterior gases, liquids or airborne matterwill be excluded from the channel 68.

Subsequent to infusing fluid from the syringe 82 into the fluid flowpathway 68, hence into the catheter 36 and the hand H of the patient,the syringe 82 with lockingly engaged shielded cannula 80 can beslidably withdrawn from the injection site 34. Subsequent to thiswithdrawal, the septum 52 reseals the opening 66 therein.

The opening 66 will repeatedly reseal, when the piercing member 98 isremoved, provided that the pressure (in the septum 52 of the opening 66)created by interaction of the septum material properties and compressionsupplied by the housing exceeds the pressure challenge of the fluidcontained within. Blunt cannula do not haphazardly core, lacerate, orotherwise damage the sealing interface 66 as conventional needles do,thereby allowing repeatable resealability. However, septum materialproperties, thickness, and compression allow resealability for a finitenumber of conventional needle insertions. The combination injection site34 and catheter 36 then return to its pre-infusion, sealed condition.

FIGS. 5A and 5B illustrate the pre-slit injection site 34 used incombination with a blunt cannula 80a. The cannula 80a includes a hollowbody portion 92a with a luer flange 94a, a piercing member 98a, andmanually operable elongated locking members 100a and 100b. Alternately,a tubing member could be affixed to the hollow body portion 92.

Curved end regions 100c of the members 100a and 100b slidably engage thesecond end 44 of the housing 40 when the piercing member 98a of theblunt cannula 80a has been forced through the pre-formed opening 66,best illustrated in FIG. 58. The embodiment illustrated in FIGS. 5A and5B has the advantage that the infusion cannula 80a cannot accidentallydisengage from the pre-slit septum 34 during the fluid infusion process.It will be understood that while spring-like deflecting members 100a and100b are illustrated in FIGS. 5A and 5B that other forms of lockingmembers are within the spirit and scope of the present invention.

FIG. 6 illustrates an alternate pre-slit injection site 34a. A tubingmember 102 can be fixedly attached to the cylindrical hollow fluid flowmember 46. The embodiment 34a of FIG. 6 utilizes the same structure forthe septum 52 including the tapered surface 60 and the underlyingannular channel 62 as does the embodiment 34 in FIG. 3. The shieldedcannula 80 can be utilized with the injection site 34a as previouslydescribed.

In the event that it is desirable to infuse solution from a container104 with a connectional port 106, a fluid administration set 110 of aconventional variety may be utilized. The set 110 includes a spikeconnector 112 at a first end. The spike connector 112 is designed topierce the port 106 of the container 104. The set 110 can also carry aslidably engageable connector 114 of a known type at a second end. Asillustrated in FIG. 7, the connector 114 can slidably engage the hollowcylindrical member 92 of the shielded cannula 80, thereby placing theinterior fluid of the container 104 into fluid communication with thetubing member 102.

FIG. 8 illustrates yet another alternate 80b to the shielded cannula 80.The piercing member 98 carries a tubing member 118 fixedly attachedthereto. The tubing member 118 could be coupled at a second end to acontainer such as the container 104.

The present pre-slit injection site can be directly affixed to acontainer 120 as illustrated in FIG. 9. The container 120 includes arigid hollow cylindrical access port 122 affixed thereto. The accessport 122 includes a fluid flow channel 124 in fluid flow communicationwith the interior of the container 120. Sealingly affixed to the port122 is a pre-slit injection site 126.

The site 126 includes a cylindrical housing 128 which carries at a firstend 130 a septum 132 with a slit 134 formed therein. The first end 130has been swaged to form an annular U-shaped retaining member 136. Theretaining member 136 in turn forms a domed exterior peripheral surface138 on the septum 132.

The first end 130 also includes a tapered interior force applyingsurface 140 and an annular channel 142 underlying the septum 132. Asdiscussed previously, the channel 142 provides a space into which theseptum 132 can deform when a blunt cannula is forced through theresealable opening 134.

Further, as illustrated in FIG. 9, the injection site 126 can be coveredby a removable cover 146 of a type used with the conventional port 106of the bag 104.

While the bag 120 is illustrated formed with two ports, the conventionalpierceable port 106 and the pre-slit injection site 126, it will beunderstood that as an alternate (FIG. 10), a container 150 could beformed which includes only the pre-slit injection port 126. Theremovable cover 146 could be used in combination with the container 150.

As illustrated in FIG. 11, the pre-slit injection site 126 can beutilized for the purpose of injecting fluid from the syringe 82, coupledto the shielded cannula 80, into the container 150. When so utilized,the blunt piercing member 98 is used to place the interior fluidcontaining region 90 of the syringe into fluid flow communication withthe interior of the container 150.

FIGS. 12 and 13 illustrate a fluid flow coupling system 151 having as afirst element a pre-slit injection site 126a. The site 126a is the sameas the site 126 except for a plurality of exterior threads 153 formed onan exterior peripheral surface 155 of the housing 128a. A second elementof the coupling system 151 is a shielded blunt cannula 157.

The shielded blunt cannula 157 is sealingly affixed to a flexible tubingmember 159 by means of a proximal hollow cylindrical member 161. Themember 161 extends into a hollow cylindrical shield 163 to form a bluntpiercing member 165.

The shield 163 carries, on an interior peripheral surface, a set ofcoupling threads 165. The threads 165 match the threads 153.

The two connector elements 126a and 157 slidably engage one another whenthe shielded cannula 157 moves in an axial direction 167 toward theinjection site 126a. The blunt piercing member 165 penetrates the septum132a.

The coupling member 157 can then be rotated in a direction 169 such theinterior set of threads 165 carried thereon engages the exterior set ofthreads 153. As a result, the two coupling members 126a and 157 arelockingly engaged together with the insertion member 165 extendingthrough the opening 134a in the septum 132a. Hence, fluids can flow fromthe container 150a via the connector system 126a and 157 through thetubing member 159 to the recipient.

Injection sites of the type described above are also usable inconnection with other fluid flow coupling components. For example, withrespect to FIG. 14, a pre-slit injection site 160 of the type describedabove can be used in combination with a spike connector 162 of aconventional variety. Spike connectors such as the spike connector 162can be used to pierce conventional ports such as the port 106 of thecontainer 104 (FIG. 6). When the spike connector 162 is so used, thepre-slit injection site 160 can then be utilized for the purpose ofcoupling to other fluid administration sets.

The injection site 160 illustrates an alternate form of swaging thefirst end 42c for the purpose of retaining the septum 52c therein. Thefirst end 42c can be swaged so as to form an annularly shaped, spiral,spring-like member 164. The member 164 has a free end 164a which engagesthe exterior dome-shaped peripheral surface 54c of the septum 52c. Thespiral, spring-like swaged member 164 will tend to uncoil, therebycontinuously applying axial force to the septum 52c and maintaining thedomed exterior peripheral surface 54c.

In yet another alternate, FIG. 15 illustrates a pre-slit injection site166 formed in a Y-junction member 168. The Y-junction member 168 isfixedly attached to first and second tubing members 170 and 172respectively.

As an alternate to forming the slit 66d completely through the septum52d, as illustrated in FIG. 16, a slit 66e can be formed only partlythrough the septum 52e. Such a structure has the further advantage that,until used for the first time, the septum 52e is completely sealed.

The septum 52e can be formed in two parts. One part can have a slit,such as the slit 66e, extending entirely therethrough. A second part canbe formed without a slit. These two parts can be located adjacent oneanother in the first end 42e of the injection site.

The slit 66e may be longer on the top of the septum than the bottom.This feature aids blunt cannula alignment with the slit upon insertion,and aids resealability by minimizing the critical slit sealing interfacearea.

In accordance with the present invention, the slit could have a lengthwith a range on the order of 0.03 inches (0.0762 centimeters) to 0.150inches (0.381 centimeters). Preferably, a slit length on the order of0.07 inches (0.1778 centimeters) will be used in combination with ablunt cannula having a diameter on the order of 0.1 inches (0.254centimeters).

When initially used, the blunt cannula piercing member, such as themember 98, will be forced through the slit 66a. The lower peripheralsurface 56e will then be punctured, providing access for the bluntcannula piercing member 98 into the fluid flow pathway 68e.

Pre-slit injection sites of the type described above can be utilized incombination with burette solution administration sets. One such set 176is illustrated in FIG. 17. The set 176 includes a pre-slit injectionsite 178 of the type described above. The injection site 178 is affixedto an exterior planar surface 180 of the burette 182. A removeable cover184 can be used to maintain the injection site 178 in an asepticcondition until blunt cannula 186 or 188 is inserted therethrough.

FIGS. 19 through 23 disclose a method of making a pre-slit injectionsite in accordance with the present invention. In a first step, ahousing 200 is provided. The housing 200 has an interior tapered surface202 at a first end 202a thereof. The interior peripheral surfaceterminates in an annular channel 204. A cylindrical septum 206 can beprovided adjacent the end 200a.

In a second step, the septum 206 can be forced into the end 202a of thehousing 200 and slightly deformed by the tapered peripheral surface 202using an axially moving die 210. When positioned by the die 210, theseptum 206 is located adjacent an internal annular right 212 whichbounds the annular channel 204.

In a third step, a second die 214 can be utilized to swage the end 200ainto spiral-shaped, spring-like members 200b which apply axiallydirected forces against an exterior peripheral surface 206a of theseptum 206. The axially directed forces form the flat surface 206a intoa domed exterior peripheral surface 206b as illustrated in FIG. 23.

Simultaneously, with swaging the end members 200a so as to lock theseptum 206 into the housing 200 and to form the domed exteriorperipheral surface 206b, a knife 216 can be utilized to form a slit inthe septum 206. Alternatively, the slit may be cut by a separate die ina separate step. If the septum 206 is formed as an extrusion, the slitcan be created during the extrusion process. If the septum 206 is formedby stamping from a rubber sheet, the slit can be cut during the stampingprocess. If the septum 206 is formed by compression molding, the slitcan be cut during the trimming process.

In order to extrude the slit into rod, a flat pin extrusion bushing canbe used. A trailing ribbon may be attached to the bushing. The ribbonwould prevent curing material across the slit. The ribbon or wire couldbe placed in the rod core and later stripped out leaving a slit. Aninert substance, such as silicone oil, could be coextruded in the centerof the rod to prevent curing across the slit and provide lubrication anda visible target for cannula insertion.

FIGS. 24 and 25 illustrate alternate swaging steps wherein a die 220moving axially toward the housing 200 swages the end region 200a so asto form an annular U-shaped region 200c and the exterior domedperipheral surface 206c.

The dies 214 or 220 can be formed with various alternate shaped swagingsurfaces 224, as illustrated in FIG. 26, depending on the precise shapeof the end swage which is desired. It will be understood that all suchvariations in the swaging operation are within the spirit and scope ofthe present invention.

The injection site configuration need not be limited to theconfigurations depicted in FIGS. 3 through 5B, 9, and 12 through 16.Rather, several configurations could be constructed without departingfrom the scope of this invention. Any such configuration would provide aflexible pre-slit sealing member captured in a housing which providescompression to create a seal against pressure and a void region toaccommodate deformed portions of the sealing member material only whenthe material is deformed or displaced by a blunt cannula piercingmember. One such possible configuration is depicted in FIGS. 27 and 28.

FIGS. 29 and 30 illustrate a tapered cannula structure 250 which is analternate to the tapered cannula 98. The cannula 250 includes a proximalend 252 with an interior region 254. The region 254 is in part boundedby an internal peripheral wall 256 which is formed with a standard luertaper. The tapered cannula 250 can be formed with a luer-type couplingflange 257 at the proximal end so as to be releasably connectable to thesyringe 82 as was the tapered cannula 98 previously discussed.

Extending from the proximal end 252 is a cylindrical tube having acylindrical mid-region 258 and a distal end member 260. The member 260has a generally elongated, cylindrical shape with an exterior side wall262. A centrally located, cylindrical, internal fluid flow path 264extends through the distal end member 260 and mid-region 258 in fluidflow communication with the interior region 254.

The distal end of the end member 260 has a tapered exterior surface 266.The tapered exterior surface 266 minimizes insertion force as thecannula 250 is being forced through a slit of a septum, such as the slit66 in the septum 52. The angle of taper of the surface 266 is preferablyin a range between 1 to 15 degrees.

The member 260 is also provided with a plurality of elongated grooves268. The grooves 268 in the exterior wall of the member 260 decrease thesurface area of contact at the cannula/septum interface during insertionof the cannula into the injection site 34. This reduced exterior contactsurface area decreases the frictional component of the insertion force.

In one embodiment, the tapered blunt cannula 250 may have overallinsertion length, corresponding to combined axial lengths of mid-region258 and end member 260, on the order of 0.375 inches 0.9525centimeters).

An alternate cannula structure 280 is illustrated in FIGS. 31, 32, and33. The cannula structure 280 includes a proximal end region 282corresponding to the end region 252 of the cannula 250. The region 282includes a luer flange 283. The cannula 280 also includes a central,elongated, cylindrical region 288.

The central region 288 carries at a distal end thereof an elongatedcylindrical end member 290. The member 290 includes an exterior,peripheral, cylindrical surface 292 (FIG. 31). The surface 292 isinterrupted by a plurality of spaced-apart, elongated slots or apertures294. The slots 294 are defined by first and second spaced-apart,elongated, parallel side surfaces 294a and 294b. Each of the slotsterminates in an end surface 294c at the central region 288.

A fluid flow path 294d extends through the cannula 280. The flow path294d is in fluid flow communication with the slots 294.

Between the slots 294, at a distal end of the region 290, the exteriorsurface 292 terminates in tapered end regions 298 to facilitateinsertion of the cannula into a pre-slit injection site. The slots 294themselves also function to decrease the surface contact area, and thisfurther minimizes the insertion force.

The slots 294 are oriented substantially 90 degrees apart around alongitudinal axis 300. The slots 294 increase the internal flow pathcross-section. This increases the fluid flow rate.

The slots 294 also provide for enhanced dispersion characteristics owingto the fluid flowing radially out through the slots 294. This radialflow, effecting as change in fluid flow direction of about 90 degrees,promotes flushing and dispersion of fluid through the injection site 34.

Another embodiment of a blunt cannula 310 is illustrated in FIGS. 34through 37. The cannula 310 is formed with an enlarged proximalconnection region 312 corresponding to the region 252 of the cannula250. The region 312 includes a luer flange 313 and a central fluid flowregion 314.

An intermediate, cylindrical region 318 extends from the proximalconnection region 312. The cylindrical intermediate region 318 includesa fluid flow path 320 in communication with the fluid flow region 314.

The end region 324 extends from the region 318 and includes a firstcylindrical portion 326 into which the fluid flow path 320 extends. Theregion 326 terminates in a tapered exterior surface 328. The taperedexterior surface 328 merges with a centrally located lead post or guidepost 330. The lead post 330 terminates in a hemispherical end surface332.

The lead post 330 helps locate the septum slit 66 prior to insertion andfacilitates penetration of the septum slit 66 by the cannula. The leadpost 330 facilitates insertion by providing a very low insertion forceat the beginning of the insertion step as the cannula is pushed throughthe slit, such as the slit 66.

In a preferred embodiment, the guide post 330 can have a length on theorder of 0.060 inches (0.1524 centimeters) and a diameter on the orderof 0.050 inches (0.127 centimeters).

The end region 318 includes a novel structure for increasing the flowrate and enhancing dispersion characteristics. In particular, the region318 includes three radially oriented slots 338. Each slot 338 has sides339a and 339b which each lie along a radius of the cylindrical portion326 as best illustrated in FIG. 37. The fluid flowing through thecannula 310 undergoes a change in direction (of up to about 90 degreesrelative to the cannula center line 337) in the slots 338. This changein direction increases fluid dispersion. Further, since the slot 338open radially, fluid flow can be maintained even if the end surface 332of the cannula is pushed up against any material in the system in whichthe cannula is inserted.

Another embodiment of the tapered cannula of the present invention isillustrated in FIGS. 38 through 40 and is designated generally thereinby reference numeral 340. The cannula 340 includes a proximal end 342which can include a luer coupling flange 344 for cooperating with asuitable mating structure on a syringe. The proximal end 342 alsodefines an interior region 346.

Extending from the proximal end 342 is a generally cylindricalmid-region 348. Extending from the mid-region 348 is an end member orregion 350 which includes a tapered surface 352.

The distal end of the end region 352 terminates in a blunt, arcuate endsurface 356. Defined within the mid-region 348 and end region 350 is aninternal fluid flow channel 354 which communicates with the interiorregion 346. Fluid discharges from the flow channel 354 via grooves orapertures 358 in the end region 350. The change in direction of thefluid flow as the fluid passes from the interior channel 354 through theapertures 358 improves fluid dispersion with respect to mixing orflushing in the system downstream of the cannula (e.g., the injectionsite, drug vial, etc.). The apertures 358 may also function to increasewithdrawal force or tug resistance.

Moreover, since the fluid passes radially out through the apertures 358,fluid flow through the cannula 340 can be maintained even when thedistal end surface 356 of the cannula is bottomed out or pushed againstany material in the system in which the cannula is inserted.

The structure of the cannula 340 is adapted to be constructed with aminimal lead post length (i.e., the portion of the cannula distal endbetween the end surface 356 and the interior flow channel 354). Further,the design accommodates the use of a minimal tip diameter, minimal taperangle, and minimal cannula diameter. The minimization of theseparameters results in a decrease in the peak insertion force required toproperly install the cannula in the injection site.

Preferably, the total cross-sectional flow area through the threeapertures 358 is about three times the cross-sectional flow area of theinterior channel 354. This enhances the flow rate capability comparedwith a simple open ended cylindrical flow channel of equal length.

The design of the cannula 340 also is effective in reducing or limiting"kick back" or recoil of the cannula after insertion. The resilientmaterial of the septum in an injection site can subject the cannula toforces tending to push the cannula back out of the septum. The kick backforces on the cannula 340 are minimized by the provisions of thegenerally cylindrical mid-region 348.

Another embodiment of the cannula of the present invention isillustrated in FIGS. 41 and 42 wherein the cannula embodiment isdesignated generally therein by the reference numeral 360. The cannula360 includes a proximal end 362 defining an interior region 364 andhaving a luer flange 366 for connection to a suitable mating engagingstructure.

A generally cylindrical mid-region 366 extends from the proximal end362, and an end region 368 extends from the mid-region 366. As with theprevious embodiment of the cannula 340 illustrated in FIGS. 38 through40, the embodiment of the cannula 360 minimizes kick back or recoilowing to the provision of a substantially cylindrical mid-region 366.This design also increases withdrawal or tug resistance.

A generally cylindrical internal flow channel 370 extends through theend region 368 and mid-region 366 in communication with the interiorregion 364 of the proximal end region 362. The end region 368 isprovided with a tapered surface 372. The design permits the use of avery small taper to minimize the insertion force.

Further, the design permits the cannula 360 to be constructed with asmall tip diameter, small taper angle, and small cannula diameter so asto reduce the peak insertion force.

Another embodiment of the cannula of the present invention isillustrated in FIGS. 43 through 44 and is designated generally thereinby reference numeral 380. The cannula 380 includes a proximal end 382with a luer flange 384. An interior fluid flow region 386 is defined onthe interior of the proximal end 382.

Extending from the proximal end 382 is a mid-region 388. A distal endregion 390 extends from the mid-region 388. An internal fluid flowchannel or path 392 extends through the end region 390 and mid-region388, and is in communication with the interior flow region 386.

The end region 390 has an exterior tapered surface 394. This facilitatesinsertion of the cannula into the injection site. In contrast, themid-region 388 is generally cylindrical so as to minimize kick back andincrease the withdrawal force or tug resistance.

Further, to provide even greater withdrawal force, the mid-region 388includes an annular barb 396. The barb 396 has a sufficient radius so asto preclude damage to the septum of the injection site and so as toaccommodate molding in a straight draw tool. The maximum diameter of theannular barb 396 may typically be on the order of 0.02 inches (0.0508centimeters) greater than the diameter of the cylindrical mid-region388. Although the barb 396 functions to prevent inadvertent removal ofthe cannula 380 from the septum of the injection site, removal of thecannula 380 can still be achieved by entering a sufficiently greataxially directed removal force on the cannula 380.

Still another embodiment is illustrated in FIG. 45 which includes ablunt tapered cannula insertion member 400 for insertion into a pre-slitinjection site, the cannula 400 having a distal end region 402 with atapered exterior surface which in the preferred embodiment is anapproximately 8 degrees taper. The defined aperture 404 for fluid flowis disposed at the end 406 of the distal end region 402. The end 406includes a radiused tip defined by a radius of approximately 0.01 inch(0.025 centimeters). The radiused tip reduces insertion force, assistsin locating the slit in the injection site and in addition has thepractical advantage of facilitating complete filling of the cannula moldcavity.

The tapered surface of the distal end region 402 has an axial length ofapproximately 0.10 inch in the preferred embodiment, Adjacent to thetapered distal end region is a generally cylindrical region 408 forentering into the injection site behind the distal end region 402,thereby reducing kick back during insertion. The generally cylindricalregion 408 has a small draft angle such as about one-half degree.

The force required to insert any of the above-discussed embodiments ofthe blunt tapered cannula into the septum of the injection site dependsupon a number of factors: friction at the cannula/septum interface,cannula diameter, cannula taper angle, and degree of septum compression.The cannula/septum interface friction is, in turn, dependent uponlubrication, if any, material properties, and surface finish. It will beunderstood that the friction at the cannula/septem interface can bereduced by providing a smoother surface finish on the cannula (e.g., bysand blasting the cannula exterior surface) or by molding the cannula soas to produce a matte finish. Conventional lubricants can also be usedto further reduce the friction and thereby lower the insertion forcerequired.

In the embodiments of the cannulae described herein, the mid-region andthe tapered distal end region may be alternatively characterized astogether forming at least one tube defining a fluid flow path thereinwith the tube having a distal end region for penetrating the injectionsite.

In preferred contemplated embodiments, the exterior surface of thedistal end region may have a taper angle as small as between 1 and 15degrees.

Further, a locking means, such as the locking arms 100a and 100bdiscussed with reference to FIGS. 5A and 5B, may be provided on thecannula embodiments illustrated in FIGS. 29 through 44 to permit thecannulae to be releasably locked to the injection site.

The above described insertion members, usable as part of a bluntcannula, are preferably molded of a plastic formulation includingsilicone or other lubricant. The use of silicone or other lubricantincreases the ease of insertion of that member into the pre-slitinjection site.

FIG. 46 shows a blunt cannula member, generally at 410, for use with thepre-slit injection sites disclosed herein. The blunt cannula member 410generally has a hollow cylindrical portion 412 and a blunt cannulaportion 414. The blunt cannula member 410 is preferably of one-piecemolded, rigid plastic, with a through bore 416 extending through theblunt cannula portion and communicating with the hollow cylindricalportion.

The hollow cylindrical portion has a pair of opposed raised flanges orthreads 418 for threaded engagement with other devices, for example,syringes, administration sets and the like. Internally, the hollowcylindrical portion 412 may also be adapted for attachment to otherdevices. For example, the internal surface of the cylindrical portionmay define a tapered female luer surface for interfitting with thestandard male luer connectors utilized in many medical devices, as iswell known in the medical field. The hollow cylindrical portion 412 mayalso include a pair of opposed flat surfaces 420 for cooperation with atip protector or shield such as depicted in FIG. 47, which is describedbelow.

The blunt cannula portion 414 extends generally axially from the hollowcylindrical portion 410. The cannula portion is generally cylindricalthroughout the greater part of its length, with a tapered end portion424, which narrows to the blunt end edge 426.

FIG. 47 is an enlarged view of a hollow shield or tip protector 428 forcovering and protecting a blunt cannula, such as, for example, the bluntcannula portion 414 of blunt cannula member 410 shown at FIG. 46 orother blunt cannulae as disclosed herein. The shield 428 has a generallyelongated housing 430, which is open at one end for receiving the bluntcannula. At the open end, the interior surface 432 of the shieldgenerally corresponds to the shape of the exterior surface of the bluntcannula portion 412, i.e., it is generally cylindrical, with a pair ofopposed flat surfaces 434 matching the flat surfaces 420 of the bluntcannula device 410. Further, either surfaces 432 or 434 can be providedwith standing ribs to control the depth of insertion of the bluntcannula portion 414 into housing 430. The matching flat surfaces of theshield and the blunt cannula device allow a user to secure the bluntcannula onto a syringe or similar device, for example, without exposingthe cannula portion 414 to touch contamination. When access to the bluntcannula is required, the shield may simply be slidably removed from thecannula. As can be appreciated, the outer surface of the shield 428 canbe shaped in such a manner or provided with a roughened finish to assistthe user in gripping or removing shield 428 from the cannula.

Typically, the blunt cannula 410 or other blunt cannula device andshield 428 would be provided in a joined sterile configuration. Theshield 428 can be provided with channels to facilitate gassterilization. The user preferably leaves the shield on to preventinadvertent contamination when attaching the blunt cannula to the matingproduct, e.g., the male luer fitting of a syringe or administration set.The matching flat surfaces 432 of the shield and 420 of the bluntcannula act as a wrench to allow any twisting force applied to theshield to be transmitted to the cannula, e.g., for threading the cannulaonto a luer lock device or for applying a twisting force in making aluer slip connection.

FIG. 48 shows what is commonly referred to as a heparin lock, generallyat 436, employing a pre-slit injection site 442 and other features ofthe present invention. The heparin lock 436 may be attached, forexample, to the end of a venous catheter.

During intravenous therapy, it is not unusual for the administration ofliquid to be interrupted from time to time. Instead of performing a newcatheterization procedure each time administration is to be restarted,it is often preferable to utilize the same catheter, thus reducing thenumber of catheterization procedures, more colloquially referred to asthe number of "sticks," and reducing the trauma and risk associated witheach such procedure.

To maintain the patency of the catheter during interruption, and preventblood from clotting and clogging the catheter, it is a common practiceto attach an injection site over the catheter an fill the catheter withheparin or other anticoagulant. The heparin lock 436 shown in FIG. 48 isfor attaching to a patient's catheter for maintaining patency of thecatheter during interruption in fluid flow.

The heparin lock 436, also shown in FIGS. 49 and 50, has a first endportion 438 in the form of a male luer connector for sealingly engaginga complementary female tapered luer surface on the patient's catheter(see cross-sectional view in FIG. 50). The other end of the heparin lock436 includes a pre-slit injection site 442 of the type previouslydiscussed in detail. An axial fluid flow passageway 444 communicatesbetween the pre-slit injection site and the end of the male luer forfluid flow therebetween.

The tapered exterior surface of the male luer 438 is substantiallysurrounded by generally cylindrical gripping collar 446. Threads 448 areprovided on the interior surface of the collar for threadedly engaging astandard luer lock connector, as is often found on intravenous catheterdevices. The exterior surface of the collar 446 is generally arcuate incross-sectional shape (as best seen in FIGS. 49 and 50), to provide agripping surface. The surface curves generally outwardly in a directiontoward the pre-slit injection site 442. This allows the nurse, physicianor attending staff member to grip the heparin lock and to reduce anyforce exerted during entry of a blunt cannula into the pre-slitinjection site form being transmitted to the venous catheter. Forimprovement in the gripping, a series of axial grooves 450 are providedin the exterior surface of the collar 446.

In accordance with other aspects of the present invention, the heparinlock includes features which allow attachment to various styles or typesof blunt cannulae. For example, as best seen in FIG. 48, threads 452 areprovided on the exterior surface of the cannula for threaded lockingengagement to a blunt cannula device of the type having an interiorlythreaded sleeve or shield, such as depicted in FIG. 50. The heparin lock436 also includes a generally radially-extending shoulder 454 forlocking retention of resilient gripping fingers on a blunt cannuladevice of the type shown in FIG. 49.

As a safety measure, and to prevent staff confusion of an injection siteof the present invention with other injection sites which are for usewith needles, a visual identifier is also provided with the heparin lockof FIG. 48. Such an identifier may also be provided with the otherpre-slit injection site devices described above. The identifier may takethe form of any unique color or configuration which allows the staffmember to determine that the heparin lock 436 embodies the presentinvention and is intended for use with blunt cannulae. In the preferredembodiment, however, the visual identifier comprises a distinct coloridentifier and, more particularly, is a brightly colored ring 456 (FIG.48) circumscribing the pre-slit injection site 442. While the colorselected may vary depending on application, it should be a color whichis distinct from and in contrast to the color of any plastic used in themanufacture of the heparin lock.

As noted earlier, the heparin lock 436 depicted in FIG. 48 may be usedwith a variety of styles or types of blunt end cannula devices. Forexample, the heparin lock may be used with a bare blunt end cannula,such as that depicted in FIG. 46, which does not lock onto the heparinlock. Alternatively, as shown in FIG. 49, the heparin lock may be usedin combination with a blunt cannula device 458 which utilizes a pair ofresilient gripping fingers 460 for retaining the blunt cannula in joinedrelationship with the heparin lock. The blunt cannula device 458depicted in FIG. 49 has a generally cylindrical, hollow base or bodyportion 462 and a blunt cannula portion 464 substantially as describedearlier in connection with FIG. 46 or with the other figures of thepresent inventions. A fluid flow path 463 extends through the bluntcannula portion and communicates with a female luer connection 465defined in the hollow body portion for fluid flow through the bluntcannula device. Flanges or threads 467 on the body portion permit theattachment of a male luer lock connector to the blunt cannula device.

Each of the gripping fingers 460 is mounted to the body portion of theblunt cannula device by an intermediate radially extending wall portion466. The gripping fingers have radially inwardly directed retentionmeans 468 at one end for engaging against radial shoulder 454, andgripping means 470 at the other end for squeezing and spreading theretention means to release the blunt cannula device from the heparinlock. In the as-molded condition, the gripping fingers are biasedradially inwardly, toward the blunt cannula portion 464. Because of thenatural resilience of the plastic, the retention end of the fingers maybe spread by squeezing the gripping end of the fingers. The naturalresilience will hold the retention means in the lock position (shown inFIG. 49) until manually released.

When used in combination with a heparin lock such as depicted in FIG.48, the blunt cannula device 458 may be attached by simply pushing theblunt cannula into the pre-slit injection site 442. A forward facingtapered surface 472 (FIG. 49) in front of the threads engages a similartapered surface 474 on the retention means 468 so as to naturally spreadthe fingers 460 apart as the blunt cannula is forced into the pre-slitinjection site. After the blunt cannula is inserted into pre-slitinjection site sufficiently far so that the retention means are beyondthe radial shoulder 454, the gripping fingers will snap inwardly behindthe shoulder, holding the blunt cannula in the position depicted in FIG.49. To withdraw the blunt cannula, the user need simply squeeze thegripping end 470 of the handles, which will spread the retention meansof the fingers and release the blunt cannula device from the heparinlock.

The heparin lock of FIG. 48 is also useful with a blunt cannula device475 having an internally threaded shield or sleeve, such as depicted inFIG. 50. FIG. 50 illustrates the blunt cannula device 475 as it firstenters the pre-slit injection site 442 of the heparin lock and prior toengagement with the heparin lock threads 452. the blunt cannula deviceshown in FIG. 50 has a generally cylindrical outer wall 476 and atransverse end wall 478. A blunt cannula 480 extends through the endwall. The blunt cannula may be constructed in generally the same manneras the blunt cannula portion depicted in FIG. 46 or in accordance withthe other embodiments of the present invention.

The cylindrical outer wall 476 preferably extends beyond the tip end ofthe blunt cannula to protect the cannula against inadvertent touchcontamination. The interior surface of the cylindrical wall ispreferably threaded at 482 for threadedly engaging the device to whichthe blunt cannula is attached, such as the heparin lock depicted in FIG.48. As noted above, FIG. 50 depicts the blunt cannula device 475 at aninitial entry position. Further insertion of the blunt cannula andsimultaneous turning of the blunt cannula device results in threadedlocking engagement between the blunt cannula device 47 and the heparinlock.

The blunt cannula 480 of the blunt cannula device 475 is in fluidcommunication with an entry port, generally defined by wall 484, whichextends in the opposite direction of the blunt cannula, from the otherside of the transverse wall. The entry port is for attachment to otherdevices such as syringes, tubing, administration sets or the like, andmay take such form as is appropriate for the particular device to whichit is attached. The entry port 484 preferably has a tapered innersurface for receiving a standard male luer fitting of a syringe or thelike, and may include external threads or flanges 485 for attachment toa luer lock. Another embodiment provides the entry port 484 as having atapered inner surface for receiving a tubing fit. A fluid passageway 486extends continuously through the entry port and the cannula portion forflow therebetween.

FIG. 51 shows, in cross-sectional view, a further alternative device 492which may employ the pre-slit injection site of the present invention.The pre-slit injection site device 492 depicted in FIG. 51 is an in-linedevice, preferably for adding medication to a fluid stream, removing asample from a fluid stream, or similar application. The device depictedin FIG. 51 has a fluid entry port 494 at one end, a fluid exit port 496at the other end, and a fluid passageway 498 communicating directlybetween the entry and exit ports. The inlet and outlet may have suchadditional features as are useful connecting the injection site devicewithin a fluid flow path. As depicted, the inlet defines a slightlytapered female surface and the outlet defines a similarly female taperedsurface which are preferably joined by solvent bonding a similarattachment to plastic tubing of an administration set, extension set orthe like. Standard luer fittings or surfaces could also be provided atthe inlet or outlet, as desired.

For injecting liquid into the fluid stream or sampling the fluid stream,the device has a side channel 496 which communicates between a pre-slitseptum 502 made and assembled in accordance with the present invention,and the fluid passageway 498. The septum 502 is made as described above,and mounted and held in position by a swaged-over wall 504, aspreviously described, which may include a colored identifier ring aroundthe septum.

In accordance with the present invention, a blunt cannula, such ascannula 506, may be inserted through the pre-slit septum for injectingfluid into the liquid stream flowing between the inlet and outlet, orfor taking samples of the fluid stream.

The in-line injection site device 492 shown in FIG. 51 may be used incombination with a bare blunt cannula, such as that depicted in FIG. 51,or may be used in combination with the blunt cannula device 458,depicted in FIG. 49, when a locking relationship between the bluntcannula and injection site is desired.

As depicted, for example, in FIG. 52, the blunt cannula device 458 maybe attached in a secure locking relationship to the in-line injectionsite 492. As shown there, the in-line injection site has a radiallyextending shoulder 508 on each side of the housing, for engaging againstthe retention means 468 on the end of the resilient gripping fingers460. As with the heparin lock, the in-line injection site also includesa generally tapered surface 510 defined on the exterior surface forspreading the retention means as the blunt cannula is inserted into theinjection site. As was described above, insertion of the blunt cannulainto the injection site results in the retention means being spread bythe tapered surface 510 and, as the blunt cannula is inserted farther,the retention means snap into a locking position behind the radialshoulder 508. In this arrangement, the blunt cannula is securely lockedonto the injection site and inadvertent withdrawal is thus prevented. Toremove the blunt cannula from the in-line injection site, the grippingends 470 of the resilient fingers are squeezed, causing spreading of theretention means 468 and release from the injection site. The cannula maythen be simply removed by withdrawing it from the injection site.

FIG. 53 depicts yet a further embodiment of the present invention. Thatfigure depicts a blunt cannula device 512 embodying the presentinvention in combination with a syringe 514. The blunt cannula device512 has a generally cylindrical outer wall 516 which encloses andsubstantially protects a blunt cannula portion 518. The blunt cannulaportion is attached to and extends from an intermediate transverseinterior wall 520. The blunt cannula device 512 may be attached to asyringe in various ways. As depicted, however, the syringe 514 has aglass barrel wall which is tightly press fit into one end of thecylindrical outer wall, extending therewithin to the transverse wall520.

Although various syringes may be used in connection with the bluntcannula device 512 without departing from the present invention, thesyringe depicted in FIG. 53 is of the type prefilled with a medicalliquid such as heparin. Although it does not form a part of the presentinvention, for purposes of completeness, the syringe depicted in FIG. 53has a pair of resilient pistons 522 spaced apart, with the fluid to bedispensed contained between the pistons. A plunger rod 524 pushes thepistons forward until the forward most piston engages against an entryport 526 which extends in a direction opposite the blunt cannula 518.The forwardmost piston has a frangible portion, which is pierced by theentry port, releasing the liquid contained between the pistons forexpulsion through the blunt cannula.

In accordance with the present invention, the blunt cannula portion 518is substantially protected from inadvertent touch contamination by theouter cylindrical wall 516. To permit the blunt cannula to be used,however, with the in-line injection site 492 or a similar device, a pairof opposed, generally U-shaped recesses 528 are provided in thecylindrical wall for receiving the inlet and outlet portions 494, 496 ofthe in-line injection site when the cannula is attached to it. Thisarrangement is depicted in a perspective view in FIG. 56. As shownthere, the blunt cannula device 512 may be attached to the in-lineinjection site by inserting the blunt cannula portion into the pre-slitinjection site, with the U-shaped recesses 528 receive the inlet andoutlet portions 494, 496 of the in-line injection site, thus allowingthe bare cannula to be inserted sufficiently far into the pre-slitinjection site.

FIG. 54 shows a shield or tip protector 530 for a blunt cannula deviceof the type shown in FIG. 53. The tip protector 530 has a generallycylindrical outer wall 532 with raised ribs 534 for gripping. Thecylindrical wall is sized to slip over the end cylindrical wall 514 ofthe blunt cannula device 512, and is sufficiently long to extend beyondthe U-shaped recesses to completely enclose and protect the bluntcannula 518 during shipping, storing and between uses, if so desired.

Concentrically disposed within the cylindrical wall 532, the tipprotector has an axially extending, hollow tube 536 for slidablyreceiving the blunt cannula 518 therewithin. The shield or tip protector530 would typically be attached to the blunt cannula device 512 duringmanufacture, and removed when the syringe and blunt cannula device areused. If so desired, it may be reattached between uses to protect thecannula from any further contamination.

FIG. 55 is an alternative embodiment of the blunt cannula device shownin FIG. 53, and is depicted without a syringe attached to it. As shownin FIG. 55, the blunt cannula device 538 similarly has a cylindricalouter wall 540, a transverse intermediate inner wall 542, a bluntcannula 544 extending axially from the transverse intermediate wall andan entry port 546 extending in the opposite direction from the bluntcannula. The essential difference between this embodiment and the oneshown in FIG. 53 is the absence of the U-shaped recesses for use with anin-line injection site such as depicted in FIG. 56. For ease ofattachment to an injection site, the inner surface of the cylindricalwall is preferably tapered at 548.

The in-line injection site device 492 shown in FIG. 51 is ideally suitedfor use in an arterial or venous line blood sampling system such as theone disclosed in U.S. Pat. No. 4,673,386 entitled Blood Sampler Device,issued Jun. 16, 1987, in the name of Mark Gordon. The entire Gordonpatent is incorporated herein by reference as if fully set out herein,specifically FIGS. 1-6, the specification from Column 1, line 1, toColumn 5, line 7, Claims 1-14, and the Abstract.

The in-line injection site device 492 of the present invention wouldreplace the stopcock or three-way valve 49 of the Gordon patent at theblood withdrawal site. FIG. 57 shows the blood sampling system of thepresent invention with the in-line injection site device 492. The fluidentry port 494 and fluid exit port 496 of in-line injection site 492 arepreferably joined to the plastic tubing 555 of the administration set bysolvent bonding, as opposed to standard luer fittings, to reduce therisk of contamination. Using the pre-slit injection site of the presentinvention rather than a conventional stopcock at the blood withdrawalsite also reduces the risk of contamination.

Referring to FIG. 57, the blood sampling system of the present inventionincludes a blood reservoir assembly 550, an in-line injection sitedevice 492 (sampling site), a shielded blunt cannula 577 with syringe582, and a blood transfer unit 552. The reservoir and sampling site areconnected via bonded connections to pressure tubing 555 which is in turnbonded to a female luer connector 551 at the inlet side of the reservoirfor attachment to a pressure transducer (not shown). The transducer ispositioned in-line between the reservoir and a flush valve, downstreamfrom a fluid supply. A male luer connector 553 is bonded to the pressuretubing at the outlet side of the sampling site for attachment to apatient catheter. The entire system is intended to be disposable.

As disclosed and described in the Gordon patent, the reservoir is anin-line syringe type device with housing, cap, plunger and seal whichwhen actuated draws into the internal cavity a blood/saline mixture ofapproximately 5 cc for the standard adult and approximately 3 cc for thepediatric patient. The fluid is drawn from the patient side as opposedto the transducer side due to the high fluid restriction provided by amicro-bore hole which exists in currently manufactured flush devices.This clears the line between the patient and the sampling site of salinesolution or other IV fluid and therefore permits a pure blood sample tobe taken from the sampling site. After the sample has been taken, theblood/saline mixture in the reservoir is returned to the patient.

The present invention preferably provides a sampling site housing in theshape of a "Z" as shown in FIG. 58, although the T-shaped housing shownin FIG. 51 may also be used. The "Z" housing 558 has an inlet port 560at the bottom leading to the reservoir and an outlet port 562 at the topleading to the patient to provide for ease of debubbling during initialfilling of the patient line with fluid and ease of blood clearing fromthe reservoir following the sampling process. The top portion 564 of thehousing contains a pre-slit septum 566 made and assembled in accordancewith the present invention and specifically as shown in FIG. 51. An armor pole mount plate 568 may also be provided for holding the samplingsite housing. In a preferred embodiment, the bottom portion 570 of thehousing mates with and is bonded to raised pedestal 572. Cradle 574 mayalso be provided in the mounting plate, if desired, to receive inletport 560 for alignment purposes. Slots 576 may also be provided fortaping or strapping the mount plate to a patient's arm. Other means ofaligning the Z-site on the mounting plate include slots in the pedestalmating with tabs or bumps on the interior of the bottom portion of theZ-site housing. The mounting plate can also be molded integral with theZ-site if desired.

A shielded blunt cannula with a sampling syringe such as the one shownin FIG. 53 is used with the blood sampling system of the presentinvention. The blunt cannula is inserted through the pre-slit septum forwithdrawing the blood sample as shown in FIG. 51. The blunt cannula andpre-slit injection site replace conventional needles and injection portsor luer lock attachment to the sampling stopcock. The blunt cannula andpre-slit injection site provide the advantage of reducing or eliminatingthe risk of needle sticks and blood touch contamination. The bluntcannula and pre-slit injection site also permit repeated cannulainsertion and withdrawal without coring which is experienced withconventional needles and injection sites.

Referrring to FIG. 59, preferably the shielded blunt cannula 577 usedwith the blood sampling system of the present invention has a rotatingshield 578 with U-shaped slots 580 that fit over the inlet and outletports of the sampling site housing as described above with reference toFIG. 56. The rotating shield prevents detachment of the blunt cannulafrom the sampling syringe if the syringe is rotated while attached tothe sampling site. In another preferred embodiment, a blunt cannula andshield can be integrally molded into the syringe barrel as shown in FIG.55. This would eliminate the need for a rotating shield since thecannula cannot become disengaged.

In the blood sampling system of the present invention shown in FIG. 57,a blood transfer unit 552 is also provided. The blood transfer unitconsists of a pre-slit injection site 554 made and assembled inaccordance with the present invention and a shroud covered needle 556.Referring to FIG. 60, the blood transfer unit is shown with the shroud584 disengaged from the needle and pre-slit injection site assembly 585.The needle is bonded to an adapter, a plastic piece with a threaded maleconnector 590 at one end (the needle end) and a male luer connector atthe other end (the pre-slit injection site end). The shroud 584 ispreferably a clear plastic housing with a female threaded connector 588which mates with the male threaded connector 590. The pre-slit injectionsite has a tubular or cylindrical housing 592 deep enough to receive theblunt cannula 579. The housing has a female luer connector (not shown)that mates with the male luer connector (not shown) on the adapter. In apreferred embodiment, the shroud and pre-slit injection site housing aremolded as one piece.

When a blood sample is transferred from the syringe to an evacuatedtube, the blunt cannula on the syringe is inserted into the pre-slitinjection site 554 and the blood sample flows through the tubularhousing 592 of the pre-slit injection site, through the needle 556 intothe evacuated tube. The tube is positioned within the shroud to protectthe user from needle pricks and blood contamination. Preferably, needle556 is covered by a rubber sleeve or protector. The sleeve could also bemade of any elastomeric material, such as silicone and the like. Whenthe rubber covered needle pierces the rubber stopper of the evacuatedtube, the rubber sleeve pushes back from the needle. When the needle isremoved from the rubber stopper, the rubber sleeve slides down to coverthe needle and prevent blood drops from contacting the user. The rubbersleeve also allows the blood transfer unit to be used for more than oneevacuated tube without permitting blood to leak through the needle whenthe evacuated tube is removed.

From the foregoing, it will be observed that numerous variations andmodifications may be effected without departing from the spirit andscope of the novel concept of the invention. It is to be understood thatno limitation with respect to the specific apparatus illustrated hereinis intended or should be inferred. It is, of course, intended to coverby the appended claims all such modifications as fall within the scopeof the claims.

What is claimed is:
 1. A blood sampling system for withdrawing bloodfrom a patient, comprising;(a) tubing adapted to be connected at one endto the patient in fluid communication with the patient's vascular systemand at the other end to a fluid supply; (b) a reservoir assemblyconnected in-line to said tubing between the patient end and the fluidsupply end, comprising a flow through reservoir housing having innerwalls defining an interior chamber of holding fluid, a first port influid communication with said interior chamber connected to said tubingleading to the fluid supply, a second port in fluid communication withsaid interior chamber connected to said tubing leading to the patient, aretractable plunger disposed within said reservoir housing, said plungerformed in a complementary configuration to said interior chamber andadapted to traverse said chamber, and a sealing member disposed aboutsaid plunger in slidable sealing engagement with said inner walls ofsaid interior chamber, said plunger adapted to be slidably retractedwithin said interior chamber to create negative pressure within saidchamber, said negative pressure being effective to draw fluid from saidtubing into said chamber for temporarily storing said fluid in saidchamber and to draw blood from said patient into said tubing, saidplunger adapted to be slidably projected toward said ports forreintroducing said stored fluid into said tubing; and (c) a samplingsite connected in-line to the tubing between said patient end and saidreservoir assembly, said sampling site, comprising a flow throughsampling site housing having a first port connected to said tubingleading to said reservoir assembly and a second port connected to saidtubing leading to the patient, thereby defining a fluid channel throughsaid sampling site housing, means defining an access aperture in saidsampling site housing in communication with said fluid channel, andflexible means carried by said sampling site housing for sealing saidaccess aperture, said means having a resealable opening therein suchthat a blunt cannula can be sealingly inserted through said opening andplaced in fluid flow communication with said channel to withdraw bloodfrom said tubing and such that said blunt cannula can be removedtherefrom with said flexible means interacting with said housing so asto reseal said resealable opening.
 2. A blood sampling system forwithdrawing blood from a patient, comprising:(a) tubing adapted to beconnected at one end to the patient in fluid communication with thepatient's vascular system and at the other end to a fluid supply; (b) areservoir assembly connected in-line to said tubing between the patientend and the fluid supply end, comprising a flow through reservoirhousing having inner walls defining an interior chamber for holdingfluid, a first port in fluid communication with said interior chamberconnected to said tubing leading to the fluid supply, a second port influid communication with said interior chamber connected to said tubingleading to the patient, a retractable plunger disposed within saidreservoir housing, said plunger formed in a complementary configurationto said interior chamber and adapted to traverse said chamber, and asealing member disposed about said plunger in slidable sealingengagement with said inner walls of said interior chamber, said plungeradapted to be slidably retracted within said interior chamber to createnegative pressure within said chamber, said negative pressure beingeffective to draw fluid from said tubing into said chamber fortemporarily storing said fluid in said chamber and to draw blood fromsaid patient into said tubing, said plunger adapted to be slidablyprojected toward said ports for reintroducing said stored fluid intosaid tubing; and (c) a sampling site connected in-line to said tubingbetween the patient end and said reservoir assembly, said sampling sitecomprising a flow through sampling site housing having a first portconnected to said tubing leading to the reservoir assembly and a secondport connected to said tubing leading to the patient, thereby defining afluid channel through said sampling site housing, means defining anaccess aperture in said sampling site housing in communication with saidfluid channel, and flexible means carried by said sampling site housingfor sealing said access aperture, said means having a resealable openingtherein such that a blunt cannula can be sealingly inserted through saidopening and placed in fluid flow communication with said channel towithdraw blood from said tubing and such that said blunt cannula can beremoved therefrom with said flexible means interacting with saidsampling site housing so as to reseal said resealable opening; (d) saidblunt cannula comprising an elongated member with a fluid flow channelextending generally axially therewithin and through a distal end of saidmember, said elongated member being generally cylindrically along asubstantial portion of its length and terminating in a generally tapereddistal end portion having a blunt end edge.
 3. A blood sampling systemaccording to claim 1 or 2, wherein said first port of said sampling sitehousing leading to said reservoir assembly is located at a lower portionof said sampling site housing and said second port of said sampling sitehousing leading to the patient is located at a higher portion of saidsampling site housing, thereby providing for ease of debubbling duringinitial filling of said tubing with fluid from the fluid supply and easeof clearing fluid from said reservoir assembly when said plunger isprojected toward said ports in said reservoir assembly.
 4. A bloodsampling system according to claim 2, wherein said blunt cannula furthercomprises a substantially cylindrical sheath surrounding said elongatedmember and being at least coextensive with and spaced apart from saidelongated member to protect said member from inadvertent touchcontamination.
 5. A blood sampling system according to claim 4, whereinsaid sheath has two slots formed therein at its distal end, said slotsdisposed opposite each other in said sheath, said slots being adapted tofit over said first and second ports of said sampling site housing toaid in aligning said blunt cannula with said sampling site.
 6. A bloodsampling system according to claim 1 or 2, further comprising an adapterfor transferring fluid from said blunt cannula to an evacuated tubehaving a sealed end, comprising:(a) an injection site having asubstantially cylindrical injection site housing and flexible meanscarried by said injection site housing for sealing one end of saidinjection site housing, said flexible means having a resealable openingtherein such that the blunt cannula can be sealingly inserted throughsaid opening and can be removed therefrom with said flexible meansinteracting with said injection site housing so as to reseal saidresealable opening; (b) a needle attached to the other end of saidinjection site housing in fluid flow communication with said injectionsite housing; (c) a shroud attached to said injection site housing, saidshroud covering said needle and adapted to receive said evacuated tubesuch that said evacuated tube can be inserted into said shroud andpushed against said needle until said needle pierces said sealed end,thereby enabling transfer of fluid from said blunt cannula to saidevacuated tube.
 7. An adapter according to claim 6, further comprisingan elastomeric sleeve covering said needle such that when said evacuatedtube is pushed against said needle, said sleeve is pushed back exposingthe needle as the needle pierces the sealed end of the evacuated tubeand as the evacuated tube is removed from the needle, the sleeve slidesback over the needle to cover the needle.
 8. A method for withdrawing ablood sample from a patient line which is in communication with thepatient's vascular system at one end and connected to a fluid supply atthe other end, comprising the steps of:(a) disposing a reservoirassembly in said patient line between said fluid supply end and thepatient end of said line; (b) disposing a sampling site in said patientline between said reservoir assembly and the patient end of said line,said sampling site comprising a flow through housing having a first portleading to the reservoir assembly and a second port leading to thepatient, thereby defining a fluid channel through said housing, meansdefining an access aperture in said housing in communication with saidfluid channel, and flexible means carried by said housing for sealingsaid access aperture, said means having a resealable opening thereinsuch that a blunt cannula can be sealingly inserted through said openingand placed in fluid flow communication with said channel and can beremoved therefrom with said flexible means interacting with said housingso as to reseal said resealable opening; (c) disabling fluid flow fromthe fluid supply to said reservoir assembly; (d) drawing fluid containedin said patient line into said reservoir assembly, said drawing beingeffective to draw blood from the patient into said patient line; (e)inserting said blunt cannula through said resealable opening of saidsampling site to withdraw blood from said patient line; and (f) removingsaid blunt cannula from said sampling site, said flexible means of saidsampling site thereby interacting with said sampling site housing so asto reseal said resealable opening.
 9. A method according to claim 8,further comprising the step of:(g) transferring said blood withdrawnfrom said sampling site to an evacuated tube having a sealed end,through an adapter comprising an injection site having a substantiallycylindrical injection site housing and flexible means carried by saidinjection site housing for sealing one end of said injection sitehousing, said flexible means having a resealable opening therein suchthat the blunt cannula can be sealingly inserted through said openingand can be removed therefrom with said flexible means interacting withsaid injection site housing so as to reseal said resealable opening, anda needle connected to the other end of said injection site housing influid communication with said injection site housing, a shroud connectedto said injection site housing and surrounding said needle, said shroudadapted to receive said evacuated tube such that said evacuated tube canbe inserted into said shroud and pushed against said needle until saidneedle pierces said sealed end, thereby enabling transfer of said bloodfrom said blunt cannula to said evacuated tube.